| 摘要 |
PURPOSE:To reduce the time required for a control of color balance, by providing a level detecting means that detects the fact that the output level of pickup tube is set at a level appropriate to the color balance control on the basis of an automatic control of the aperture state of iris. CONSTITUTION:The color balance control circuit consists of an iris 11, a level detecting means 30, a level comparing means 33 that compares plural color signal levels meaning the output of a pickup tube based on the level of a color signal, a gain control means 34 that varies the relative levels of said color signals, and a controller 8 that controls not only the means 34 but the iris 11. A color balance control command is given to the controller 8, and then the working control signal is supplied to the means 33 from the controller 8 when the detection output is obtained from the means 30. On the basis of the comparison output of the means 33, the means 34 is controlled by the controller 8. Thus the color balance is controlled. |
